But this has been a unique period of opportunity for investors in the single-family rental space. A historic level of distressed homes for sale, price declines that have made housing remarkably cheap and high demand for rental units amid constrained credit conditions have combined to create an unprecedented opportunity for investors to buy vacant, foreclosed homes in bulk and rent them out.

Institutional investors with deep pockets have swarmed into the business, with private-equity player Blackstone leading the charge.

Housing bears fear that these big investors will pull out of the housing market once competition increases and returns dry up and first-time homebuyers and trade-up buyers who have been squeezed out of the market may still not step in to fill the void.

Morgan Stanley is optimistic, however. For one, they expect homeownership to continue to decline for the next few years and the renting class to increase. Converting distressed stock to rentals will help meet this growing demand.

Secondly, while the yields currently are modest at 5% to 6% after capex, home price appreciation will augment cash flow yields, driving a return on capital to above 10%. Moreover, the analysts expect margins to expand over time. Rents should climb 3% to 4% while expenses grow by a slower 2%.

Another big driver would be financing. The Wall Street Journal reported Wednesday that Blackstone and Deutsche Bank are in talks to securitize rental payments on 1,500 to 1,700 rental properties.

Securitizing payments from single-family rentals has its challenges. There is no data on the payment track record of people renting previously foreclosed homes.